<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <!-- <script src="./outscript"></script> -->

    <script>
        var a = null;
        a = Boolean(a);
        console.log(typeof a ,a)

        var b = undefined;
        b = Boolean(b);
        console.log(typeof b ,b)


    </script>
</head>
<body>

</body>
</html>